This invention relates to an amphibious vehicle capable of operation on land and in the water.
Amphibious vehicles adopting pontoons and other means for floatation and stability in the water, as well as inflatable pontoons adapted for use with various water borne structures, are known in the prior art. Prior art amphibious vehicles are generally designed to ride low in the water to inhibit capsizing. Such vehicles are typically operated at low speeds as further precaution against excessive rolling or capsizing. Other prior art vehicles, such as work boats that are not amphibious, have floatation elements which are permanently inflated. Such flotation elements extend outwardly by moveable arms for additional stability during periods of stationary work. This particular design is not well suited for use with an amphibious vehicle because the mechanism securing the floatation elements may fail due to the loads resulting from waves and vehicle movement.
Various means are employed in the prior art for floatation of amphibious vehicles. U.S. Pat. No. 5,868,093 discloses an amphibious vehicle having disposed within its body cavity a plurality of hollow cells for floatation. Buoyancy tanks that articulate between an operative and inoperative position by piston and cylinder means are disclosed in U.S. Pat. No. 5,315,950. In the inoperative position the tanks are disposed parallel to one another above the roof of the vehicle. Similarly, U.S. Pat. No. 4,802,433 discloses an amphibious vehicle having pontoons that articulate between a position for water travel and a storage position for road travel, which is on top of the vehicle. Both the ""950 and ""433 patents pertain to recreational vehicles that presumably make use of federal, state and local highways, roads and streets. Thus, the design of these vehicles makes it necessary to employ fairly elaborate mechanisms to stow the pontoons in a position that complies with vehicle width restrictions imposed by the various governmental bodies responsible for those pathways. U.S. Pat. No. 5,687,669 discloses a vehicle employing pontoon assemblies pivotally coupled to a vehicle""s frame so that the pontoons may be stowed within the width of the frame for highway, road and street use. Wheels are disposed on each pontoon assembly for land use.
Float means are disclosed by U.S. Pat. No. 5,727,494 for a cockpit body. The float means may be a plurality of retractable pontoons, or of a plurality of longitudinally extending hulls integrally formed within the vehicle. Such float means keep the vehicle afloat and provide stability during marine operation. U.S. Pat. No. 4,459,932 discloses an amphibious vehicle employing inflatable members disposed in the front, rear and one side of the vehicle, with another inflatable element directly beneath the chassis adapted to serve as a float for the vehicle. Resilient traction elements are also disclosed that are disposed inside and around the inflatable elements. Also in the prior art, a buoyant boat hull having substantially horizontal cylinder recesses along its sides for receiving a pair of helical augers is disclosed by U.S. Pat. No. 5,203,274. These recesses are specially adapted to confine water between the screw threads and project it directly to the rear of the vehicle for more efficient forward thrust.
Another prior art invention disclosed in U.S. Pat. No. 5,875,730 discloses a device for attaching inflatable pontoons to rigid keels. An elongated, substantially arcuate member conforming substantially to the circumference of a pontoon is affixed to a rigid keel. The member is preferably made of a weldable metal such as aluminum and is welded to the keel for receiving the pontoon.
The present invention is an amphibious vehicle having inflatable pontoons adapted for use as a passenger vehicle on both land and in water. The vehicle may be used, for example, for transporting tourists in areas where the touring route includes travel over land and in the water for the passengers"" optimal viewing and educational enjoyment. As such, it is important for the vehicle to make quick transitions between land and water to minimize delay, which reduces the risk of passenger discontent from having to wait for an operator to make mechanical or other adjustments to the vehicle that passengers may view as being unreasonably lengthy.
The present invention is adapted for use on public highways, roads and streets by ensuring that the vehicle complies with vehicle width restrictions for use on these venues. For use in the water, the vehicle employs inflatable pontoons that operate with minimal delay and which extend the width of the vehicle while in the water to provide greater vehicle stability to reduce the risk of excessive rolling or capsizing. In one embodiment of the present invention, the vehicle includes one or more pontoons disposed in a substantially horizontal configuration along each side of the vehicle""s main body. The pontoons are securely disposed within recessed cavities formed within the main body so that when they are deflated they may be withdrawn within each cavity so that the width of the vehicle complies with vehicle width restrictions for use on highways, roads and streets. In one embodiment of the present invention, the means for securing a pontoon within a recessed cavity includes a fastening means, such as Velcro, a clamping means such as clamps or bolts affixed to the main body along the upper and lower edges of the cavity that grasp center seam flaps extending longitudinally along the exterior of the pontoon, and a substantially elastic member or members that are affixed to the main body and extend around the exterior of the pontoon. The substantially elastic member not only helps to secure the pontoon within the recessed cavity, but due to its elastic properties, it also ensures the pontoon is fully withdrawn within the confines of the cavity when the pontoon is deflated to prevent the pontoon from drooping downwardly. The elastic member stretches outward when the inflatable pontoon expands and contracts when the inflatable pontoon is deflated to pull the inflatable pontoon within the recessed cavity. It also provides protection for the pontoon against external physical damage. With the pontoon secured within the cavity, a hinged decorative door may be closed to cover the pontoon for aesthetic purposes and to protect it from damage due to weathering. Further, the decorative door may be pushed up out of the water by the inflatable pontoon when the inflatable pontoon is inflated and will close over the inflatable pontoon when deflated by means of a spring loaded hinge. Alternatively, the door may be opened and closed manually.
The inflatable pontoons of the present invention may be cylindrical tubes which may be of varying diameters and lengths depending on the design of the vehicle and conditions within which the vehicle will be used. In one embodiment of the present invention, the pontoons are disposed on each side of the vehicle between the front and rear wheels. This placement provides optimum stability for the vehicle shown in the FIGS. while the vehicle is in the water. Other placements may be employed as a function of vehicle design and operational requirements. The pontoons are inflated and deflated by means of conventional air generators such as pressurized air tanks or blowers. The air generators are connected to piping having valves and pressure regulators to fill each pontoon to the desired pressure, which is typically done just prior to the vehicle entering the water. The air generators are also used to deflate the pontoons for use on land by switching or reversing the position of valves. Multiple volumes of inflatable pontoons and multiple air supplies may be provided for safety to prevent sinking in the event of a component failure. Each pontoon may also include a plurality of internal chambers to prevent total deflation of a pontoon in the event of damage. In one embodiment of the present invention, each pontoon has four discrete internal chambers that are air tight so that if one deflates the others will not. Further, the ends of each pontoon may be tapered to facilitate movement of the vehicle through the water with reduced water friction.